Hydroxy carboxylic acid esters of long chain alcohols



Patented July 5, 1938 UNITED STATES PATENT OFFICE HYDBOXY CARBOXYLICACID ESTERS OF LONG CHAIN ALCOHOLS No Drawing. Application December 4,1934, Se-

rial No. 755,909.

16 Claims.

This invention relates to new compositions of matter, and particularlyto esters of 10 to 14 carbon atom alcohols with certain saturatedaliphatic hydroxy carboxylic acids.

This case is a continuation in part of copending application Serial No.543,386, filed July 10, 1931 which issued on March 12, 1935 as U. 8.Patent 1,993,736.

The esters of the present invention may be made by various means, forexample as follows:

A. By heating a hydroxy acid with an-alcohol, for example, citric acidwith dodecyl alcohol.

B. By heating a long chain alcohol with an ester of a volatile alcoholwith a hydroxy acid, for example, tetradecyl alcohol with ethyl lactate.Catalysts such as litharge, and sodium or aluminum alcoholates may beused.

C. By forming an ester of an unsaturated acid followed by hydration. forexample, forming didodecyl maleate by heating dodecyl alcohol withmaleic anhydride followed by sulfation of the ester and hydrolysis tothe hydroxy ester.

D. By heating the cyclic double esters. the lactides, with long-chainalcohols, for example, heating tetradecyl alcohol with digl'ycolide.

E. By heating the sodium salts of the hydroxy acids with long-chainalkyl halides, for example, sodium lactate with decyl bromide.

Having outlined above the general principles and procedures of theinvention, the following exempliflcations thereof are added for purposesof illustration but not in limitation:

Example 1.Tn'dodecyl citrate Nineteen parts by weight of citric acid and61 parts by weight of dodecyl alcohol were heated at 200 C. for 17hours. Carbon dioxide was passed thru the reaction mixture during theheating. The product was a yellow oil which solidified slowly at 21-24C. The product was subjected to vacuum distillation and 24 parts byweight were removed by distilling up to 250 C. at 20 mm. .The producthad a saponification number of 237 and melted at-26" C.

Example 2.-Dodecyl lactate Two hundred flve parts by weight of dodecylalcohol, 118 parts by weight of ethyl lactate, 400 parts by weight oftoluene and 10 parts by weight of litharge were heated under a 4 ft.reflux column until the temperature of the distilling liquid wasconstant at 105-110 C. The product was filtered and washed with saltwater and the toluene removed by distillation. On fractionaldistillation of the product, 82 parts by weight In Canada August 2, 1933of a water-white oil was obtained which boiled at 150 C./2 mm. and had asaponification number of 214.

Example 3.--Dodecyl tartrate yielding, for example, the lauric acidester of dodecyl lactate.

Other hydroxy acid esters may be substituted for the dodecyl lactate,such as octyl hydracrylate, tetradecyl tartrate, dodecyl citrate,tetradecyl malate, and dodecyl trihydroxy-glutarate. In addition othermonobasic aliphatic acids besides lauric may be used, such as acetic,

butyric, caprylic, capric, myristic, palmitic, oleic,

etc. It will be understood that in place of the acid which is used foresterifying the hydroxy acid ester, the anhydride, acyl halide or otheracid derivatives may be used. In addition to sulfuric acid, hydrochloricacid and benzenesulfonic acid may be employed as catalysts in order tospeed up the esterification. While a solvent immiscible with water ispreferred in this process in order to remove the water formed byesteriflcation, it is not necessary. These acylated derivatives oflong-chain esters of hydroxy acids are particularly useful as softenersin cellulose derivative compositions comprising cellulose nitrate orcellulose ethers, such as ethyl, butyl, or benzyl cellulose andparticularly useful in the manufacture of artificial leather. They mayalso be employed with natural resins or synthetic resins, withbituminous substances, with other plasticizers, with solvents, pigments,fillers, etc., for use in molding, as adhesives, or binders, as

impregnating, toughening and waterproofing agents for paper, wood,textiles, stone, etc. In those cases where a softening agent is desiredwhich combines the features of good stability on aging and a. moderatelyhigh exudation temperature, these new compositions of matter are ofutility, and in this connection are superior to castor oil. Further,these derivatives do not have the tendency to become rancid and therebyshow advantage over castor oil which is used as a softener in artificialleather.

Example 4.-Coconut alcohol esters of lactic acid Coconut oil wassubjected to carboxylic hydrogenation and the resulting product waswashed with water to remove water-soluble materials. After drying in asuitable manner, such as with sodium sulfate, the resulting mixture ofcoconut alcohols had a molecular weight of about 200. Fractionation ofthis mixture of alcohols indicated that it had approximately thefollowing composition: hexyl alcohol 4 parts, octyl alcohol 81 parts,decyl alcohol 60 parts, dodecyl alcohol 390 parts, tetradecyl alcohol160 parts, cetyl alcohol parts. octadecyl alcohol 55 parts, and eicosylalcohol 15 parts. Two hundred parts by weight of the mixture ofalcohols, 118 parts by weight of ethyl lactate, 400 parts by weight oftoluene, and 10 parts by weight of litharge were heated under a 4 ft.fractionating column until the temperature of the distilling liquid wasconstant at 105-ll0 C. The product was filtered and washed with saltwater and the toluene recovered by distillation. The residue was ayellow colored viscous oil composed of the various alcohol esters oflactic acid in which the dodecyl ester predominated. In place of theabove mixture of alcohols, there may be used a mixture of alcoholsrepresenting an intermediate fraction isolated in the fractionation ofcoconut alcohols, that is found particularly useful for plasticizingcellulose nitrate compositions and is composed of decyl alcohol 3 parts,dodecyl alcohol 39 parts, tetradecyl alcohol 16 parts, cetyl alcohqwlilwllarts, and octadecyl alcohol 3 parts. For certain applicationssuch as in combinations with nitrocellulose, it is preferred to uselactates of a mixture of alcohols as represented by the above examplesin place of pure dodecyl lactate since the mixture of esters is morereadily retained by plastic compositions and does not have a tendency toexude.

In jplace of the coconut oil'hydrogenated in theabove example, coconutoil acids, palm kernel oil or palm kernel oil acids or other essentiallysaturated fatty oils or acids therefrom may be used and the alcoholstherefrom esterified as above.

Saturated aliphatic low molecular weight bydroxy carboxylic acids ingeneral may be used including glycolic acid, hydracrylic acid, tartaricacid, citric acid, malic acid, trihydroxyglutaric acid, and betahydroxybutyric acid. By saturated aliphatic low molecular weight hydroxycarboxylic acid is meant a saturated aliphatic hydroxy carboxylic acidhaving up to six carbon atoms.

Straight chain aliphatic primary alcohols of 10 to 14 carbon atoms aregenerally useful in the preparation of these esters and include not onlythe pure alcohols, but also the mixture of alcohols obtainable by thecarboxyllc hydrogenation of essentially saturated fatty oils such ascoconut oil or palm kernel oil, 'orthe acids derivable from these oilsby saponification or the esters thereof with-monohydric alcohols.

While esters of alcohols in the range of carbon atoms of 10 to 14 areincluded within' the scope of the present invention, certain esterswithin that range are preferred for various purposes. Thus, dodecyllactate is preferred as a plasticizer to decyl and tetradecyl lactate.Esters of monobasic acids are preferred to those of polybasic acids.Thus. dodecyl salicylate or dodecyl lactate is preferred to dodecylcitrate or dodecyl tartrate as an intermediate for sulfation. Further,esters of monobasic hydroxy fatty acids, for example dodecyl lactate,are preferred to esters of aromatic acids, such as dodecyl salicylate,for use as medltizens.

The preferred method of making the esters of hydroxy acids of thepresent invention consists in reacting the long chain alcohol with anester of the hydroxy acid with a more volatile alcohol.

The compounds of this invention may be used in the preparation oflacquers and enamels for coating metal, wood, fabric paper, and wirescreen, dopes for coating fabrics, moistureproof lacquers for coatingregenerated cellulose, etc., and in plastic compositions to be used inthe manufacture of toiletware, sheeting, rods, tubes, safety glassinterlayers, dentures, etc. Certain of the acid esters, for examples thecitrates, are effective antioxidants for edible oils.

The hydroxy acid esters of the present invention are also of use in thatthey may be esterified yielding, for example, the laurlc acid of dodecyllactate, which ester and the mixture com prising the same, coconut oilfatty acid esters of the lactate of coconut oil alcohols, are of use asplasticizers for nitrocellulose, for example, in coated fabrics. Thehydroxy acid esters are also of use in that they may be etherified mostconveniently through thehalide ester of the hydroxy acid ester byreacting the same with a sodium salt of an alcohol or phenol, for.example, sodium ethylate, benzylate, phenolate,; naphtholate,dodecylate, etc.

The long chain esters of this invention-are high-boiliri'g -jcompoundsof low volatility and are useful as plasticizers for cellulosederivatives. Amyl lactate, for example, is a solvent for cellulosederivatives but is too volatile and will not remain in a cellulosecomposition for a suflicient length of time to be considered aplasticizer. Dodecyl lactate (B. P. C. at 2 mm.) is sufficientlynon-volatile to serve as an acceptable plasticizer for cellulosederivatives. Insolubility in water is an important property of compoundsfor many industrial applications. Amyl lactate is considerably moresoluble in water than dodecyl lactate, hence dodecyl lactate ispreferred to amyl lactate for use, for example, in cellulose derivativecompositions. Dodecyl lactate is even less volatile than decyl lactateand is less soluble in water than decyl lactate, hence in applicationswhere compounds of a more wax-like nature are required, dodecyl lactateis preferred to decyl lactate. The waxy nature of octadecyl lactaterenders it less compatible with cellulose deriva tives than dodecyllactate and for this application dodecyl lactate is preferred tooctadecyl lactate.

The above description and examples are intended to be illustrative only.Any modification of or variation therefrom which conforms to the spiritof the invention is intended to be included within the scope of theclaims.

I claim:

1. Dodecyl lactate.

2. An ester of a straight chain primary alcohol of 10 to 14 carbon atomswith a saturated aliphatic low molecular weight hydroxy carboxylic acid.

3. The ester of claim 2 wherein the acid is a monocarboxylic acid.

4. An ester composition wherein the mixture of alcohols obtainable bythe carboxylic reduction of the acyl radicals of an essentiallysaturated fatty oil, said mixture being comprised principally of dodecylalcohol, is esterifled by a saturated aliphatic low molecular weighthydroxy carboxyllc acid.

5. Ah ester composition wherein the mixture of alcohols obtainable bythe c-arboxylic reduction of the acyl radicals of coconut oil, saidmixture being comprised principally of dodecyl alcohol, is esterified bya saturated aliphatic low molecular weight hydroxy carboxylic acid.

6. The ester composition of claim 5 wherein the acid is a monocarboxylicacid.

7. A dodecyl ester of a saturated aliphatic low molecular weight hydroxycarboxylic acid.

8. A dodecyl ester of a. saturated aliphatic low molecular weighthydroxy monocarboxylic acid.

9. An ester composition wherein the mixture of alcohols obtainable bythe carboxylic reduction of the acyl radicals of coconut 011, saidmixture being comprised principally of dodecyl alcohol, is esterified bylactic acid.

10. An ester of a straight chain primary alcohol of 10 to 14 carbonatoms with lactic acid.

11. A tetradecyl ester of a saturated aliphatic low molecular weighthydroxy carboxylic acid.

12. A process for the preparation of esters which comprises heating asaturated straight chain aliphatic alcohol of ten to fourteen carbonatoms with a member of the class consisting of saturated aliphatic lowmolecular weight hydroxy carboxylic acids and their esters with volatilealcohols.

13. An ester of a straight chain primary alcohol of 10 to 14 carbonatoms with a saturated aliphatic low molecular weight hydroxy carboxylicacid of the class consisting of lactic, glycolic, hydracrylic, tartaric,citric, malic, trihydroxyglutaric and beta hydroxybutyric acids.

14. An ester composition wherein the mixture of alcohols obtainable bythe carboxylic reduction of the acyl radicals of an essentiallysaturated fatty oii, said mixture being comprised principally of dodecylalcohol, is esterified by a saturated aliphatic low molecular weighthydroxy carboxylic acid of the class consisting of lactic, glycolic,hydracrylic, tartaric, citric, malic, trihydroxyglutaric and betahydroxybutyric acids.

15. An ester composition wherein the mixture of alcohols obtainable bythe carboxylic reduction of the acyl radicals of coconut oil, saidmixture being comprised principally of dodecyl alcohol, is esterified bya saturated aliphatic low molecular weight hydroxy carboxylic acid ofthe class consisting of lactic, glycolic, hydracrylic, tartaric, citric,malic, trihydroxyglutaric and beta hydroxybutyric acids.

16. An ester of a straight chain primary alcohol of 10 to 14 carbonatoms with glycolic acid.

GEORGE D. GRAVES.

CERTIFICATE OF CORRECTION.

.Patent No. 2,122,716.

GEORGE D GRAVES.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 1,second column, line 11, for neurtla read neutral; page 2, second column,line 7, for meditizens read plasticizersf and that the said LettersPatent should be read with this correctiontherein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 15th day of Noveinber, A. D. 1958.

(Seal) Henry Van Aredale Acting Commissioner of Patents.

tion of the acyl radicals of an essentially saturated fatty oil, saidmixture being comprised principally of dodecyl alcohol, is esterifled bya saturated aliphatic low molecular weight hydroxy carboxyllc acid.

5. Ah ester composition wherein the mixture of alcohols obtainable bythe c-arboxylic reduction of the acyl radicals of coconut oil, saidmixture being comprised principally of dodecyl alcohol, is esterified bya saturated aliphatic low molecular weight hydroxy carboxylic acid.

6. The ester composition of claim 5 wherein the acid is a monocarboxylicacid.

7. A dodecyl ester of a saturated aliphatic low molecular weight hydroxycarboxylic acid.

8. A dodecyl ester of a. saturated aliphatic low molecular weighthydroxy monocarboxylic acid.

9. An ester composition wherein the mixture of alcohols obtainable bythe carboxylic reduction of the acyl radicals of coconut 011, saidmixture being comprised principally of dodecyl alcohol, is esterified bylactic acid.

10. An ester of a straight chain primary alcohol of 10 to 14 carbonatoms with lactic acid.

11. A tetradecyl ester of a saturated aliphatic low molecular weighthydroxy carboxylic acid.

12. A process for the preparation of esters which comprises heating asaturated straight chain aliphatic alcohol of ten to fourteen carbonatoms with a member of the class consisting of saturated aliphatic lowmolecular weight hydroxy carboxylic acids and their esters with volatilealcohols.

13. An ester of a straight chain primary alcohol of 10 to 14 carbonatoms with a saturated aliphatic low molecular weight hydroxy carboxylicacid of the class consisting of lactic, glycolic, hydracrylic, tartaric,citric, malic, trihydroxyglutaric and beta hydroxybutyric acids.

14. An ester composition wherein the mixture of alcohols obtainable bythe carboxylic reduction of the acyl radicals of an essentiallysaturated fatty oii, said mixture being comprised principally of dodecylalcohol, is esterified by a saturated aliphatic low molecular weighthydroxy carboxylic acid of the class consisting of lactic, glycolic,hydracrylic, tartaric, citric, malic, trihydroxyglutaric and betahydroxybutyric acids.

15. An ester composition wherein the mixture of alcohols obtainable bythe carboxylic reduction of the acyl radicals of coconut oil, saidmixture being comprised principally of dodecyl alcohol, is esterified bya saturated aliphatic low molecular weight hydroxy carboxylic acid ofthe class consisting of lactic, glycolic, hydracrylic, tartaric, citric,malic, trihydroxyglutaric and beta hydroxybutyric acids.

16. An ester of a straight chain primary alcohol of 10 to 14 carbonatoms with glycolic acid.

GEORGE D. GRAVES.

CERTIFICATE OF CORRECTION.

.Patent No. 2,122,716.

GEORGE D GRAVES.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 1,second column, line 11, for neurtla read neutral; page 2, second column,line 7, for meditizens read plasticizersf and that the said LettersPatent should be read with this correctiontherein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 15th day of Noveinber, A. D. 1958.

(Seal) Henry Van Aredale Acting Commissioner of Patents.

